Apparatus and method for connecting fluid lines

ABSTRACT

An apparatus and method for controlling fluid flow in a blowout preventer. In one embodiment, an apparatus for connecting fluid lines includes a socket fluid connector and a plug fluid connector. Each connector includes a flow channel. The plug fluid connector is detachably connectable to the socket fluid connector at a connection end of the plug and socket fluid connectors such that the flow channels align. Each of the socket and plug fluid connectors includes a check valve in the flow channel. The check valve is configured to prevent fluid flow through the connector flow channels while the plug and socket fluid connectors are not connected, and to enable bidirectional fluid flow through the connector flow channels while plug and socket fluid connectors are connected.

BACKGROUND

Blowout preventers (BOPs) are used in hydrocarbon drilling andproduction operations as a safety device that closes, isolates, andseals the wellbore. Blowout preventers are essentially large valvesconnected to the wellhead and comprise closure members that seal andclose the well to prevent the release of high-pressure gas or liquidsfrom the well. One type of blowout preventer used extensively in bothlow and high-pressure applications is a ram-type blowout preventer. Aram-type blowout preventer uses two opposed closure members, or rams,disposed within a specially designed housing, or body. The blowoutpreventer body has a bore aligned with the wellbore. Opposed cavitiesintersect the bore and support the rams as they move into and out of thebore. A bonnet is connected to the body on the outer end of each cavityand supports an operator system that provides the force required to movethe rams into and out of the bore.

Ram-type blowout preventers are often operated using pressurizedhydraulic fluid to control the position of the closure members relativeto the bore. The flow of hydraulic fluid to the rams is controlled viaone or more control pods of the blowout preventer. The control podprovides an electrical interface for operation of the blowout preventerfrom a drilling platform or other surface location. The control pod maybe modularized to facilitate pod testing and service by allowingindividual replacement and/or testing of each module. The control podgenerally includes an electronics package (MUX module) and a hydraulicsmodule (MOD module). The MUX module provides electrical communicationwith surface systems and electrically activated solenoid valves. Thesolenoid valves control flow of hydraulic fluid to hydraulic pilotvalves of the MOD module.

The MUX and MOD modules are coupled by a number of hydraulic connectorsthrough which pressurized fluid flows between the modules.

SUMMARY

An apparatus and method for controlling fluid flow in a blowoutpreventer. In one embodiment, an apparatus for connecting fluid linesincludes a socket fluid connector and a plug fluid connector. Eachconnector includes a flow channel. The plug fluid connector isdetachably connectable to the socket fluid connector at a connection endof the plug and socket fluid connectors such that the flow channelsalign. Each of the socket and plug fluid connectors includes a checkvalve in the flow channel. The check valve prevents fluid flow throughthe connector flow channels while the plug and socket fluid connectorsare not connected, and enables bidirectional fluid flow through theconnector flow channels while plug and socket fluid connectors areconnected.

In another embodiment, a subsea control unit for controlling a subseadevice includes a hydraulic module and an electrical control module. Thehydraulic module provides hydraulic pressure to the subsea device (e.g.,a subsea blowout preventer). The hydraulic module includes a pluralityof fluid connectors. The electrical control module electrically controlsfluid delivery to the hydraulic module. The electrical control moduleincludes a plurality of fluid connectors, each of which corresponds toand is mateable with one of the fluid connectors of the hydraulicmodule. Each of the fluid connectors comprises a check valve thatprevents fluid flow through the connector while the connectors are notmated, and allows bidirectional fluid flow through the connector whilethe connectors are mated.

In yet another embodiment, a drilling system for boring earthenformations includes a blowout preventer disposed at a subsea wellhead.The blowout preventer includes a subsea control pod that hydraulicallycontrols the blowout preventer. The control pod includes a mated pair ofhydraulic connectors that connect fluid lines of the control pod. Atleast one of the connectors includes a stem that enables bidirectionalfluid flow through the mated connectors by forcing a check valve in eachconnector open while the connectors are mated.

In a further embodiment, a fluid connector assembly includes a socketfluid connector and a plug fluid connector. Each connector includes aflow channel. The plug fluid connector is releasably connectable to thesocket fluid connector at a connection end of the plug and socket fluidconnectors wherein the flow channels are coaxially aligned. Each of thesocket and plug fluid connectors includes a check valve in the flowchannel. The check valve includes a closing seat and a moving member.The moving member has a closed position sealingly engaging the closingseat when the socket and plug connectors are not connected, and an openposition spaced apart from the closing seat when the socket and plugfluid connectors are connected. At least one of the socket and plugfluid connectors includes a stem that engages the moving members of boththe socket and plug fluid connectors when the moving members are in theopen position.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of exemplary embodiments of the invention,reference will now be made to the accompanying drawings in which:

FIG. 1 shows drilling system including a blowout preventer in accordancewith various embodiments;

FIG. 2 shows a blowout preventer control pod in accordance with variousembodiments;

FIG. 3 shows a fluid connector panel of a module of a control pod inaccordance with various embodiments;

FIG. 4 shows a mateable pair of fluid connectors in accordance withvarious embodiments;

FIG. 5 shows a mated pair of fluid connectors in accordance with variousembodiments; and

FIG. 6 shows a flow diagram for a method for controlling fluid flow in aconnector pair in accordance with various embodiments.

NOTATION AND NOMENCLATURE

Certain terms are used throughout the following description and claimsto refer to particular system components. As one skilled in the art willappreciate, companies may refer to a component by different names. Thisdocument does not intend to distinguish between components that differin name but not function. In the following discussion and in the claims,the terms “including” and “comprising” are used in an open-endedfashion, and thus should be interpreted to mean “including, but notlimited to . . . ” Also, the term “couple” or “couples” is intended tomean either an indirect or direct connection. Thus, if a first devicecouples to a second device, that connection may be through a directconnection, or through an indirect connection via other devices andconnections.

DETAILED DESCRIPTION

The following discussion is directed to various embodiments of theinvention. Although one or more of these embodiments may be preferred,the embodiments disclosed should not be interpreted, or otherwise used,as limiting the scope of the disclosure, including the claims. Inaddition, one skilled in the art will understand that the followingdescription has broad application, and the discussion of any embodimentis meant only to be exemplary of that embodiment, and not intended tointimate that the scope of the disclosure, including the claims, islimited to that embodiment.

The electronics section (MUX module) and the hydraulics section (MODmodule) of a blowout preventer control pod are hydraulically connectedby a plurality of fluid connectors of each module. When the connectorsof the modules are engaged, fluid is allowed to flow bidirectionallybetween the modules through the connectors. In a conventional system,when the connectors are disengaged while the fluid system ispressurized, the expulsion of fluid through the connectors can present asafety hazard.

Embodiments of the present disclosure include a fluid connector thatinhibits expulsion of fluid when connectors are disengaged. Theconnector includes a valve that is mechanically and positively held openwhen a pair of connectors is engaged, allowing bidirectional hydraulicflow through the connectors. When the connectors are disengaged, thevalve closes automatically, preventing expulsion of fluid from theconnectors and the attendant safety hazard.

FIG. 1 shows drilling system 150 in accordance with various embodiments.The drilling system 150 includes a drilling platform and drilling rig152, a riser 154, and a blowout preventer (BOP) 156. The BOP 156 iscoupled to a wellhead 158. The riser 154 connects the BOP 156 to thedrilling platform 152. One or more control pods 100 are coupled to theBOP 156 for actuating BOP hydraulics in response to control signalsprovided from the surface.

FIG. 2 shows the BOP control pod 100 in accordance with variousembodiments. The control pod 100 includes a MUX module 102 and a MODmodule 104. The MUX module 102 and the MOD module 104 are hydraulicallyconnectable through fluid connectors 106, 108 mounted in a connectorpanel 110, 112 of each of the MUX and MOD modules 102, 104. Each of thefluid connectors 106, 108 includes a check valve that prevents fluidexpulsion from the connectors 106, 108 while the connectors 106, 108 aredisengaged, and allows bidirectional fluid flow while the connectors106, 108 are engaged.

FIG. 3 shows a fluid connector panel 110 of module 102 of the controlpod 100 in accordance with various embodiments. The connector panel 112of the module 104 is similarly configured. The connector panel 110includes a plurality of connectors 106 and/or connectors 108 fortransferring hydraulic fluid between the module 102 and the module 104.

FIG. 4 shows a view of a longitudinal cross section of a mateable pairof fluid connectors 106, 108 in accordance with various embodiments. Asshown in FIG. 3, the connector 106 may be a socket connector, and theconnector 108 may be a plug connector. In FIG. 4 the valves of theconnectors 106, 108 are illustrated in the closed position, wherebyfluid is prevented from flowing out of the connectors 106, 108. Thegenerally cylindrical body 302 of the connector 106 includes a matingsection 304 that mates with the connector 108, and a line connectionsection 306 that is connectable to a fluid line. The sections 304, 306are joined, e.g., threaded together via threads 330, to form the body302. A groove 308 in one of the sections 304, 306 contains a sealingdevice 348 (e.g., an 0 ring, a gasket, etc.) that seals the interface310 between the sections 304, 306. The body 302 of fluid connector 106includes a passage 312 though which fluid flows through the connector106.

A portion of the passage 312 is configured to form a check valve 314.The check value 314 comprises an expanded diameter region 316 of thepassage 312 that retains a moving member 318 (i.e., a closing member),an elastic member 320 (e.g., a coil spring), and a stem 322. The movingmember 318 is a flow blocking member that operates to prevent fluid flowout of connector 106, and may be spherical, poppet-shaped, or any shapesuitable for use in a check valve in various embodiments. A first end ofthe expanded diameter region 316 forms a closing valve seat 326. Asecond end of the expanded diameter region 316 forms an opening valveseat 332. In FIG. 4 the moving member 318 is positioned against theclosing valve seat 326 sealing the connector 106 and preventing fluidfrom flowing out of the mating end of the connector 106. Expansion ofthe elastic member 320 provides the sealing force that moves the movingmember 318 into contact with the closing valve seat 326.

The stem 322 is in contact with the moving member 318 and is disposedforward of the closing valve seat 326 (i.e., towards the mating end ofthe connector 106) when the check valve 314 is closed as shown in FIG.4. In some embodiments, the stem 322 may be a part of or fixed to themoving member 318. In other embodiments, the stem 322 may be in contactwith but not fixed to the moving member 318. The stem 322 forces thevalves of connectors 106, 108 open while the connectors 106, 108 areengaged. The base of the stem 322 includes a flange 334. In someembodiments of the check valve 314, the flange 334 engages the movingmember 318 and is dimensioned to fit within a flange holding area 336proximate to the closing valve seat 326.

A socket 338 of the connector 106 is configured to receive a plug 340 ofthe connector 108 when the connectors 106, 108 are mated. A groove 342in the socket 338 retains a sealing device 344 that prevents fluid fromescaping past the sealing device 344 to ambient space while theconnectors 106, 108 are mated and under operating or test pressure.

The body 352 of the connector 108 also includes a mating section 354 anda line connection section 356. The sections 354, 356 are joined, e.g.,threaded together via threads 380, to form the body 352. A groove 358 inone of the sections 354, 356 contains a sealing device 398 (e.g., an 0ring, a gasket, etc.) that seals the interface 360 between the betweenthe sections 354, 356. The body 352 of fluid connector 108 includes apassage 362, though which fluid flows through the connector 108.

A portion of the passage 362 is configured to form a check valve 364.The check value 364 comprises an expanded diameter region 366 of thecentral passage 362 that retains a moving member 368 (i.e., a closingmember), and an elastic member 370 (e.g., a coil spring). A first end ofthe expanded diameter regions 366 forms a closing valve seat 376. Asecond end of the expanded diameter region forms an opening valve seat382. In FIG. 4, the moving member 368 is positioned against the closingvalve seat 376, sealing the connector 108. Expansion of the elasticmember 370 provides the sealing force that moves the moving member 368into contact with the closing valve seat 376.

While the connector 108 lacks a stem 322, as illustrated, in someembodiments of the connectors 106, 108, the stem 322 may be disposed inand retained by the connector 108 rather than the connector 106. Inother embodiments, both of the connectors 106, 108 may include stems322.

FIG. 5 shows a mated pair of fluid connectors 106, 108 in accordancewith various embodiments. The plug 340 of the connector 108 is withinthe socket 338 of the connector 106, and the stem 322 of the connector106 is in contact with the moving member 368 of the connector 108 andthe moving member 318 of the connector 106. The force of the stem 322against the moving members 318, 368 pushes the moving members 318, 368away from the corresponding closing valve seats 326, 376. The length ofthe stem 322 ensures that both of the moving members 318, 368 disengagefrom the forward valve seats 326, 376 when the connectors 106, 108 aremated. Thus, the stem 322 holds both check valves 314, 364 open when theconnectors 106, 108 are engaged, thereby allowing full bidirectionalflow between the connectors 106, 108 through the passages 312, 362.

In some embodiments, the check valves 314, 364 are configured toposition one of the moving members 318, 368 against a correspondingopening valve seat 332, 382 when the connectors 106, 108 are mated. InFIG. 5, the moving member 318 is positioned against the opening valveseat 332 of the connector 106. The opening valve seat 332, 382 mayinclude ridges running in the direction of the connector 106, 108longitudinal axis. The ridges allow fluid to flow freely past theopening valve seat 332, 382 and the moving member 318, 368 while themoving member 318, 368 is disposed against the opening valve seat 332,382. In some embodiments, the relative forces of the elastic members320, 370 may determine which of the moving members 318, 368 contacts theopening seat 332, 382. In other embodiments, the length of the expandedregion 316 may differ from the length of the expanded region 366 causingthe moving member 318, 368 disposed in the shorter of the expandedregions 316, 366 to contact the corresponding opening valve seat 332,382 while the connectors 106, 108 are mated.

The stem retaining and guide structure 324 may also include ridges orpassages that allow fluid to flow into and/or out of the connector 106.

Various components of the connectors 106, 108, including the sections304, 306, 354, 356, the moving members 318, 368, and the stem 322 may bemade of stainless steel or any other material suitable for use in afluid connector of a blowout preventer control pod 100.

FIG. 6 shows a flow diagram for a method for controlling fluid flow in aconnector pair 106, 108 in accordance with various embodiments. Thoughdepicted sequentially as a matter of convenience, at least some of theoperations shown can be performed in a different order and/or performedin parallel. Additionally, in some embodiments of the method 500, onlysome of the operations shown may be performed.

In block 502, the socket fluid connector 106 is brought into engagementwith the plug fluid connector 108 to allow bidirectional fluidcommunication between the connectors 106, 108.

In block 504, as the connectors 106, 108 are connected, a check valve314 in the first connector 106, and a check valve 364 in the secondconnector 108 are opened. The check valves 314, 364 are opened bymechanical engagement of the connectors 106, 108 rather than by force offluid.

To effect opening of the check valves 314, 364, in block 506, a shaft322 extending from the socket connector 106 is coupled to a flowblocking member 318 of the socket connector 106 and to a flow blockingmember 368 of the plug connector 108.

In block 508, the flow blocking member 318 of the socket connector 106and the flow blocking member 368 of the plug connector 108 aredisengaged from corresponding closing valve seats 326, 376 of the socketand plug connectors 106, 108 by force of the shaft 322. The length ofshaft 322 ensures that neither blocking member 318, 368 remains incontact with the corresponding closing valve seat 326, 376 while theconnectors 108, 108 are connected. In some embodiments, at least one ofthe blocking members 318, 368 is forced against an opening valve seat332 by the shaft 322.

In block 510, the socket connector 106 is disconnected from the plugconnector 108. The disconnection prevents fluid communication betweenthe socket connector 106 and the plug connector 108, and prevents fluidflow out of the mating end of each of the socket and plug connectors106, 108.

In block 512, as the connectors 106, 108 are unmated, the shaft 322 ofthe socket connector 106 disengages from the flow blocking member 368 ofthe plug connector 108. As the force of the shaft 322 is removed, theflow blocking member 318 of the socket connector 106 and the flowblocking member 368 of the plug connector 108 are each forced againstthe corresponding outer seat 326, 376 of the first and second connectors106, 108 by force of the elastic members 320, 370 on the blockingmembers 318, 368.

In block 514, the connectors 106, 108 are disconnected. The check valve314 in the first connector 106 and the check valve 364 in the secondconnector 108 are closed.

The above discussion is meant to be illustrative of the principles andvarious embodiments of the present invention. Numerous variations andmodifications will become apparent to those skilled in the art once theabove disclosure is fully appreciated. For example, while embodiments ofthe fluid connectors 106, 108 are described with regard to the blowoutpreventer control pod 100, those skilled in the art will understand thatvarious embodiments of the connectors 106, 108 are applicable to otherapparatus requiring fluid connectors incorporating valves that aremechanically opened and allow bidirectional fluid flow while theconnectors are mated, and prevent fluid flow out of the connectors whileunmated. It is intended that the following claims be interpreted toembrace all such variations and modifications.

What is claimed is:
 1. An apparatus for connecting fluid lines,comprising: a socket fluid connector comprising a flow channel; and aplug fluid connector comprising a flow channel, the plug fluid connectordetachably connectable to the socket fluid connector such that the flowchannels are alignable when connected; wherein each of the socket andplug fluid connectors comprises a check valve in the flow channels, eachcheck valve comprising a moving member configured to prevent fluid flowthrough the connector flow channels while the fluid connectors are notconnected; and wherein at least one of the fluid connectors furthercomprises a stem unconnected to each moving member and configured toengage each moving member when the fluid connectors are connected toenable bidirectional flow around the stem and through the flow channels.2. The apparatus of claim 1, wherein the check valve of each fluidconnector comprises: a closing seat; and a spring disposed against themoving member and configured to force the moving member against theclosing seat while the fluid connectors are not connected, therebypreventing fluid flow through the fluid connectors.
 3. The apparatus ofclaim 2, wherein the check valve of each connector comprises an expandedregion of the flow channel, the expanded region containing the movingmember; wherein the expanded regions of the connectors differ in length.4. The apparatus of claim 2, wherein the stem is configured to force themoving member of each of the fluid connectors off of the correspondingclosing seat while the connectors are connected.
 5. The apparatus ofclaim 4, wherein the length of the stem exceeds the distance between theclosing seats of the fluid connecters when the plug and socket fluidconnectors are connected.
 6. The apparatus of claim 1, wherein each ofthe fluid connectors comprises a cylindrical body comprising a firstsection forming a mating end and a second section forming a fluid lineconnection end, and wherein the sections are threadingly engaged toretain the moving member.
 7. A subsea control unit, comprising: ahydraulic module configured to provide hydraulic pressure to a subseadevice, the hydraulic module comprising fluid connectors; and anelectrical control module configured to electrically control fluiddelivery to the hydraulic module, the electrical control modulecomprising fluid connectors, each of which corresponds to and ismateable with one of the hydraulic module fluid connectors; wherein eachof the fluid connectors comprises a check valve comprising a movingmember configured to prevent fluid flow through the connector flowchannels while the fluid connectors are not connected; and wherein atleast one of the fluid connectors further comprises a stem unconnectedto each moving member and configured to engage each moving member whenthe fluid connectors are connected to enable bidirectional flow aroundthe stem and through the connector flow channels of the fluidconnectors.
 8. The subsea control unit of claim 7, wherein each checkvalve comprises: a closing seat; and a spring disposed against themoving member and configured to force the moving member against theclosing seat while the fluid connectors are not connected, therebypreventing fluid flow through the fluid connectors.
 9. The subseacontrol unit of claim 8, wherein the stem is configured to extend acrossa mating connection of the fluid connectors to cause each moving memberto recede from the corresponding closing seat while the connectors areconnected.
 10. The subsea control unit of claim 7, wherein the subseacontrol unit is coupled to a blowout preventer configured to seal awellbore, the subsea control unit configured to control operation of theblowout preventer.